The present invention relates to novel copolymers based on (meth)acrylate esters of hydroxyls and (meth)acrylate esters of hydroxyalkyl carbamates, which have been copolymerized with each other, to provide polymers having improved properties.
(Meth)acrylic polymers are known in commerce, and are formed by polymerization of one or more (meth)acrylates. These acrylic polymers can be formed into coatings, inks, and the like that have either a thermoplastic or soluble character or a thermoset or insoluble character. Such products are known to have good hydrolytic stability and other weathering characteristics particularly in comparison to polyesters and polyethers. Even though acrylic polymers have such desirable properties, the coatings industry actively seeks coatings having improved hydrolytic resistance particularly at high and low pH values over those of the current acrylics. Such improved resistance would result in products that have enhanced resistance to hostile environments such as those caused by acid rain, by air-borne chemicals, by cleaners used for dirt removal, by erosion due to dirt particles or other debris, by actinic energy such as from sunlight, and the like.
It is well known that polymers containing free hydroxyl functionality can be crosslinked with various aminoplasts such as hexamethoxymelamine and such aminoplast crosslinking agents are widely used in combination with various polymers including the acrylic polymers described above to provide coatings for a variety of substrates. However, it is believed that coating compositions based on these type polymers and crosslinking agents are less likely to withstand harsh environmental conditions due to the weak ether linkage formed between a reactive group on the crosslinking agent and the hydroxyl group of the polymer to be crosslinked.
The demanding nature of today's marketplace, which is driven by quality, energy, and environmental considerations, has developed a need for coatings with improved resistance to chemical attack from water, acids, alkalis, and the like.